Over one billion tons of pesticide products are used each year in the United States. Pesticides are an important component of pest management strategies in the public health industry. The Environmental Protection Agency (EPA) Office of Pesticide Programs registers and regulates pesticides as mandated by Federal Law. One of their mandates is to approve safer, reduced risk pesticides.
Currently there are many established methods for controlling the development of juvenile mosquito life stages, that is, both larvae and pupae, in the aquatic environment. One widely accepted procedure involves coating the surface of a body of water with a uniform film that acts to reduce the water's surface tension. This mode-of-action prevents larvae from accessing atmospheric oxygen, as their breathing siphons are inhibited from attaching to the surface of treated water and/or leading to a saturation of their tracheal systems; larval death occurs as a result of either drowning or suffocation. In addition, surface films may also impede adult mosquitoes from laying eggs.
Compositions that coat the surface of a body of water can kill mosquito larvae, that is, act as a larvicide. The compositions may also act as a larvicide without including any traditional pesticide. Because the mode of action is physical rather than chemical, mosquitoes cannot easily develop resistance.
U.S. Pat. No. 4,569,947 describes a method for controlling mosquitoes, which comprises coating the surface of a body of water containing immature forms of mosquitoes with an effective amount of one or more of a β-branched alkanol or a 1-3 mole alkoxylate thereof.
U.S. Pat. No. 4,707,359 describes a composition for controlling the breeding of insects (particularly mosquitoes) that have aquatic breeding sites. The composition comprises two components. The first component is an insoluble monomolecular layer, an insoluble foam layer, or a duplex film layer. The second component comprises a mosquito larva toxin obtained during growth of bacterial cultures. The combination of the two components provides a synergistic mixture.
U.S. Pat. No. 5,273,967 describes a method for killing immature mosquitoes in a body of water comprising spreading on the surface of the body of water a particulate, solid carbohydrate compound. The compound is non-soluble in water. The compound is spread in a quantity sufficient to hydrate at the surface of the body of water and form a substantially unbroken, floating hydrated carbohydrate layer, thereby suffocating the mosquitoes in the body of water.
U.S. Pat. No. 6,512,012 describes a method of controlling the population of mosquitoes comprising applying a surface-active composition to an aquatic environment to form a film over water within that environment. The compositions comprise at least one C6 to C11 alcohol alkoxylate.
U.S. Pat. No. 7,807,717 a method for the control of insects breeding on water surfaces. The methods consist essentially of blending in a high shear mixer the ester of a fatty acid of 10 to 25 carbon atoms, a low molecular weight alcohol, an emulsifying agent, a thickener, and water. The composition is applied to the surface of insect infested water and forms an oil film on the water.
Many types of insecticides have been used to kill mosquitoes and other insect pests. Nevertheless, many insecticides have disadvantages. Some are toxic to humans, are harmful to the environment, or have limited efficacy. Accordingly, there is a continuing need for environmentally friendly compounds having improved insecticidal properties, while being substantially non-toxic or only mildly toxic to humans.
For example, some insecticides include organic solvents, in particular, aromatic hydrocarbons, chlorinated hydrocarbons, aliphatic hydrocarbons or petroleum distillates, which in high concentrations can be hazardous to human health. As such, the replacement of a majority of an aliphatic hydrocarbon with an alternate oil is desirable.